1. Field of the Invention
The present invention relates to an internal combustion engine mounted on an a vehicle or the like, and in particular to a start control technology for an internal combustion engine
2. Description of the Related Art
In recent years, an electric motor is generally used as means for rotationally driving (i.e. cranking) a crankshaft upon starting an internal combustion engine. It is necessary for such an electric motor to rotationally drive the crankshaft while resisting a gas compression force or frictions generated in various portions of the internal combustion engine. Hence, the electric motor tends to have high rated performance and power consumption of the electric motor also tends to become large accordingly.
In particular, in the system in which the operation of the internal combustion engine is automatically stopped while the vehicle is at rest (i.e. a so-called idle stop system), since there is a possibility that stopping and starting of the driving of the internal combustion engine are repeated frequently, there is a concern that the load applied on the electric motor will become large to thereby further increase the power consumption of the electric motor.
In view of this, there has been disclosed such a technology in which a cylinder that is in its expansion stroke in the state in which the driving of the internal combustion engine is being stopped is detected and fuel is injected into that cylinder to cause combustion, to thereby reduce the load applied on the electric motor.
The above-described prior art technology is effective for internal combustion engines provided with a fuel injection valve adapted to inject fuel directly into a cylinder (i.e. so-called direct injection type internal combustion engines), but it is difficult to say that this technology is effective for internal combustion engines provided with a fuel injection valve adapted to inject fuel to an intake port of a cylinder (i.e. so-called port injection type internal combustion engines).